TERRESTRIAL MINERAL PROCESSING
My research focuses on mineral separations for industrial processes. Mineral processing is the separation of minerals based on their properties, including density, electrostatic and surface properties. The separation of minerals based on differences in their surface properties (e.g. hydrophobic/hydrophilic) is the basis of froth flotation. Froth flotation is used to concentrate a large range of metallic minerals, precious metals and industrial materials from ore. My research interests are on the optimisation and design of flotation cells and circuits, in particular linking the behaviour of the froth phase with the the separation performance. An outcome of this research is Peak Air Recovery, an optimisation strategy that improves mineral recovery, which has been tested at mine sites around the world.
Current research interests include mineral processing without water (dry processing) using gravity and electrostatic forces for mineral separation, and processing circuit design. This addresses one of the key challenges faced in the mining industry; water usage and tailings production and storage.
SPACE RESOURCE UTILISATION (SRU/ISRU)
Space Resource Utilisation (SRU), or In Situ Resource Utilisation (ISRU), is an exciting concept in which resources, such as oxygen, are extracted from the Moon, Mars and other bodies in order to enable humankind to travel further and spend longer in space. Oxygen can be produced from the lunar soil by reduction of the minerals using a number of different techniques, however each of these techniques will have different feedstock requirements. The feedstock can be produced by size and mineral separations (i.e. mineral processing or beneficiation), however conventional mineral processing techniques will have to be adapted for the lunar environment (vacuum, low gravity, no water). My research in this field is developing mineral separation techniques suitable for the Moon.
2011-present: Lecturer in Mineral Processing, Department of Earth Science and Engineering, Imperial College London
2006-2011: Post-doctoral research associate, Department of Earth Science and Engineering, Imperial College London
2002-2006: PhD, Title "Down the bank froth stability and flotation performance", Department of Chemical Engineering, University of Manchester
1998-2002: MEng, Chemical Engineering with French, UMIST
Cilliers J, Hadler K, Rasera J, Estimating the scale of space resource utilisation (SRU) operations to satisfy lunar oxygen demand, Planetary and Space Science, ISSN:0032-0633
et al., 2019, The transition from first to zero order flotation kinetics and its implications for the efficiency of large flotation cells, Minerals Engineering, Vol:132, ISSN:0892-6875, Pages:149-161
et al., 2019, Apatite enrichment by rare earth elements: A review of the effects of surface properties, Advances in Colloid and Interface Science, Vol:265, ISSN:0001-8686, Pages:14-28
Hadler K, Cilliers J, 2019, The effect of particles on surface tension and flotation froth stability, Mining, Metallurgy & Exploration, Vol:36, ISSN:2524-3470, Pages:63-69
et al., 2018, A dynamic model for level prediction in aerated tanks, Minerals Engineering, Vol:125, ISSN:0892-6875, Pages:140-149